What screws to use with plaster washers in a sagging plaster ceiling? Plaster is 3/8, lath is 1/2. Should I use 6 or 8 thickness? Coarse thread? 1-5/8 long? or 1-1/4 long is sufficient? And regular drywall screws or deck screws to prevent corrosion emanating from plaster? Thanks.

 

Let me know if this works on a ceiling as well; Plaster and Lath Reconstruction/Restoration - YouTube Lot more gravity weight, maybe, I haven't tried it up there yet...

Gary

 

I've used deck screws in the past to repair plaster ceilings. Haven't noticed any rusting problems. If you set them in slightly and plaster over them you shouldn't have a problem with any screw.

 

Thanks. Do you think 1-1/4 screws are too short and 1-5/8 should be used?

 

Many times the lathe starts to separate from the beams too.
If you putting the screws in at a beam use the 1-5/8"

 

"Let me know if this works on a ceiling as well; Plaster and Lath Reconstruction/Restoration - YouTube Lot more gravity weight, maybe, I haven't tried it up there yet..."

I haven't used the expanding foam method, I used this method on a large section of a 100 + year old heavy plaster ceiling with some heavy decorative elements. I didn't buy the expensive kit. I used Liquid nails and latex admix as a conditioner, box of 1/4X1 1 1/4" fender washers and 2 1/4"" course drywall screws. All supplies available at the local big box. It took maybe 15 tubes of adhesive to do about 60% of a 14X14 area. The screws were left in at least a week, sometimes longer til I could get back to the job. The ceiling is quite solid now. It's important to vacuum each hole but on one small section I forgot to and it still worked, I guess squirting the latex flushes the dust away. Space the screws/washers fairly close 8X8" - 10"X10" grid depending on severity of sag. I had to stop when I ran out of 100 washers and let it set a week then move on to the next.